Process of making dinitroethyleneurea



Patented May 14, 1946 mocnss OF MAKING nm'mon'rmnua- 1mm George v.Caesar. Staten Island, and Max Goldfrank, New York, N. Y., assignors toStein, Hall & Company, Inc., New York, N. Y., a corporatlon of New YorkNo Drawing. Application February 25, 1944, Serial No. 528,936

18 Claims: (Cl. 260-309) The present invention relates to a new processfor the direct liquid phase nitration of ethyleneurea to formdlnltroethyleneurea.

It is known in the prior art that ethylenedinitramine is a valuableexplosive and it has a high degree of resistance to detonation by impactor shock and yet has a high brisance or explosive strength. It may beproduced by refluxing dinitroethyleneurea with water.

The invention is concerned with the method of making the intermediateproduct, dinitroethyleneurea, which in itself is valuable as anexplosive, or it may be converted into the more valuableethylenedinitramine by hydrolyzing in boiling water,

In accordance with the prior art, it has been proposed to producedinitroethyleneurea by the nitration of ethyleneurea with very strongnitric acid. This produces relatively low yields and reugires the use ofthe expensive strong nitric 8.01

It has also been proposed in accordance with the prior art to nitrateethyleneurea with mixed nitric and sulfuric acids. This process requiresa careful control of the composition of the mixed acids, moreparticularly about 68.5% sulfuric acid, 22% nitric acid and 9.5% water.Although the yields are improved as compared with the nitration withstrong nitric acid, the reaction time is slow and the nitration must becontinued for about two hours.

In accordance with either or these prior art processes the reaction isbelieved to be as follows:

It will be seen that water is the primary by-product. This production orwater in the prior art processes involves a progressive dilution of thenitrating solution. The presence of water is undesirable not onlybecause it dilutes the acid and reduces the rate of the nitratingaction, but, since these processes are reversible, the presence or wateralso shifts the equilibrium and results in poorer yields. Thediillculties resulting from the formation of water in the nitration withstrong nitric acid is particularly striking, because as soon as thewater is formed the acid ceases to be strong.

The attempt to circumvent the presence of water by mixing with thenitric acid a water absorptive agent, or a dehydrating acid such assulfuric acid, is indicated in the prior art referred to above. Theformation of water, however, alters the proportions of the components ofthe nitrating solution and the prior art has indicated the proportionsas critical. A nitric acid nitrating solution, whether or not adehydrating acid such as sulfuric acid is used, cannot be refortifiedindefinitely, either by the addition of concentrated nitric acid or awater absorptive agent, because of the resulting undersirahle in--crease in volume. Ultimately the diluted acids must be withdrawn andreplaced. When practiced in a large scale operation the effectivedisposal of the large quantities of diluted and spent acids presents avery difficult problem.

Another disadvantage resulting from the use of mixed acids in thenitration of ethylene urea, aside from the formation of water, is thepossible production of undesirable reaction products with sulfuric acid.These may adversely afiect the stability of the dinitroethyleneurea orrequire processing to remove them.

In accordance with this invention ethyleneurea is nitrated with nitrogenpentoxide (N205) in solution in an inert non-aqueous solvent, such ashydrocarbon or a chlorinated hydrocarbon.

The ultimate products of the reaction of ethyleneurea and nitrogenpentoxide are dinitroethyleneurea and nitric acid and it is thought thatthe reaction may proceed as follows:

The process is particularly advantageous since a solvent may be selectedin which the ethyleneurea and the nitrogen pentoxlde are soluble, but inwhich the dlnitroethyleneurea is relatively insoluble. The ethyleneureamay be dissolved in the solvent and mixed with a solution of nitrogenpentoxide in the solvent and the reaction will be practically a,quantitative precipitation. It has been found that if a solution ofethyleneurea in chloroform, for example, is added to a solution ofnitrogen pentoxide in the same solvent, the dinitroethyleneureaprecipitates instantaneously in crystalline form and in substantiallyquantitative yields. The various practical advantages of such a processare so obvious that to one skilled in the art they need not beelaborated.

The precipitated crystalline dinltroeihylencurea, upon removal from thenitrating solution. may be hydrolyzed in accordance with the knownpractice by boiling in water from which the ethylenedinitramine forms inbeautiful crystals upon cooling.

As illustrative of the manner in which the invention may be practicedreference may be had to the following illustrative examples. Forconvenience, the amounts of the reactants have been given as those whichmay be easily utilized in the laboratory. The following examples aremerely illustrative and are not intended as a limitation on the scope ofthe invention.

Example I Ethyleneurea in an amount of 4.75 grams was dissolved in 85cc. of chloroform and the solution was added with agitation to 250 cc.of a solution of chloroform in which 47.2 grams of nitrogen pentoxidewas dissolved. The initial temperature of the chloroform-nitrogenpentoxide solution was 8 C. The crystalline dinitroethyleneurea wasprecipitated instantly upon the mixing of the two solutions and thetemperature rose to 29 C. The dinitroethyleneurea was then removed byfiltration and washed with cold water. The nitration period did notexceed two minutes. The yield was 8.75 grams or 89.8 of theory.Mechanical losses, plus the slight solubility of the dinitroethyleneureain the cold water, probably account for the difference.

Example II Ethyleneureau in an amount of 4.88 grams in solution in 85cc. of chloroform was added to a chloroform-nitrogen pentoxide solutionof the same amount and strength as in Example I. The initial temperaturewas -3 C. Crystalline dinitroethyleneurea formed immediately upon mixingthe solution but the nitrating period was extended for 15 minutes duringwhich the temperature was allowed to rise to 17 C. The yield was 8.93grams or 89.3% of theory, showing that the nitration period may be verybrief and still obtain a good yield.

Example In A solution containing 4.99 grams oi ethyleneurea and 85 cc.of chloroform was added to a chloroform-nitrogen pentoxide solution inthe same amount and strength as in Examples I and II. The initialtemperature was -4 C. Crystalline dinitroethyleneurea formed immediatelyand the nitration period was extended to 30 minutes during which thetemperature was allowed to rise but not exceed 1'?" C. The yield was 9.5grams or 93.3% of theory.

Example IV A solution of nitrogen pentoxide in chloroform was preparedby dissolving 37.2 grams of nitrogen pentoxide in sufficient chloroformto make 335 cc. Into this was stirred 5 grams of solid ethyleneurea. Atfirst lumps formed which were gradually dispersed during the agitation.The initial temperature was 2 C. and was permitted to rise gradually butnot exceed 15 C. The nitration was permitted to continue for 47 minutesand the yield of dinitrocthyleneurea obtained was 9.5 grams or 92.8

In all of the above examples the nilraiing solution can be further usedin nitrating an additional quantity of ethyleneurea by adding nitrogenpentoxide to the solution. The nitric acid may be removed and/orregenerated into nitrogen pentoxide as described hereinafter. Theprocess, therefore, is adaptable for a continuous method of nitration.

Any portion of the ethyleneurea in solution, but not entering into areaction is thought to remain in the solution and upon reuse of thenitrating solution will eventually be utilized. Therefore. upon theselection of optimum temperatures, etc. not only will high yields perpass be obtained, but a substantially yield would be possible in acontinuous process.

The nitrogen pentoxide and the ethyleneurea need not necessarily be achemically pure com pound to be utilized in the process. However, ifgreat purity in the final product is important, particularly for themanufacture of explosives. it is preferred to utilize ingredients whichare as chemically pure as possible so as to avoid unde sirablecomponents entering into the reaction.

The process may be practiced in any manner in which the ethyleneurea iscontacted with the nitrogen pentoxide in the solvent. This may becarried out in a. batch operation, following which the nitrated productis separated. However. the process is so well adapted to a continuous operation, and since continuous processes are desirable for commercialoperations, this may be a preferable form.

In one such continuous process the 'ethyleneurea. may be continuouslyadded to the nitrating solution in a reaction zone following which themixture is transferred to a filterin zone and the nitrated productseparated. The nitrating solution may be continuously or intermittentlyrefortifled with nitrogen pentoxide and again returned to the reactionzone to be reused.

In another process both the nitrogen pentoxide and the ethyleneurea maybe continuously introduced in the correct proportions into a solvent ina mixer. The nitrated product may be separated at the bottom as aprecipitate.

In view of the above explanation, it is obvious that many ways ofcarrying out the nitration may be suggested to one skilled in the art.and all such variations are intended to be included in the scope of thepresent invention.

The neutral solvent which is utilized in accordance with the inventionmay be selected from many available non-aqueous solvents such as thoseof coal tar 0r petroleum origin. .It is preferred to utilize a materialwhich is not reactive with any of the other materials present, i, e..the nitrogen pentoxide, the ethyleneurea, the dinitroethyieneurea andthe nitric acid. It is preferred to utilize a. olvent in which not onlythe nitrogen pentoxide is soluble but in which the ethyleneurea issoluble and the dinitroethyleneurea is insoluble. However. both theethyleneurea and the dinitroethyleneurea may be soluble or insoluble andappropriate modifications made in the process. As specific examples. ithas been found that chloroform may be used advantageously. Gen erally itis advantageous to utilize a solvent having a boiling point or rangewhich sufficiently high so that it can be maintained readily in theliquid phase during the nitration but sufficiently low so that anysolvent adhering to the nitrated product may be readily removed duringthe drying at a temperature above the boilin point of the solvent butbelow the temperature at which the dinitroethyleneurea would be harmed.Chloroform (CHCIJ) for example, is particularly advantageous in thisconnection because of its boiling point of about 61.2 C. The foregoinsolvent is mentioned merely by way of illustration and it is intendedthat the invention shall not be limited thereto. In view of the presentdisclosure as to the requirements of the solvent, those skilled in theart may readily select a solvent suitable for the conditions under whicha particular adaptation of the process is to be carried out.

The proportions of the reacting ingredients utilized may be varied overa wide range, depending upon the conditions of operation and the resultswhich it is desired to obtain. The theoretical amounts of the reactingingredients. of course, may be calculated from the formulas illustratingthe reaction.

In general the amount of the nitrogen pentoxide may be varied by varyingits concentration in the nitrating solution and also by varying theamount of nitrating solution used with the ethyleneurea. It has beenfound convenient to dissolve the nitrogen pentoxide in the proportion ofabout to 50 grams per 100 cc. of solution, preferably the range is aboutto 25 grams. The process proceeds quite well with any substantialconcentration furnishing suilicient nitrogen pentoxide for the reaction.As the nitration proceeds, additional nitrogen pentoxide may be added,if desired, to fortify and maintain the initial strength of thesolution. Alternatively, a stronger solution may be used so that theconcentration does not fall below the minimum figure which is preferredto be maintained during the entire course of the reaction.

The amount of the nitrating solution utilized in relation to thematerial to be nitrated may vary over a wide range, the minimum beingsufl'lcient to provide the desired amount of nitrogen pentoxide toaccomplish the nitration. This will depend upon whether nitrogenpentoxide is to be added during the course of the reaction or whetherthe process contemplates the presence of a suiiicient initialconcentration to complete the reaction. In general there is no objectionto a great excess of the nitrating solution to cause the reaction toproceed at the desired degree. When the process is carried outcontinuously on a large scale a great amount of solution may be used tofill a system or the apparatus. Any larger amount may be used and itwill be apparent, in view of the disclosure, that the amount is notcritical and may be varied throughout a wide range without affecting theeconomy of the process.

As a precautionary measure the temperature at which the process iscarried out should not be too high. In general a temeprature range ofthe order of 20 to 30 C. may be used, preferably 0 to 20 C, Thetemperature may be selected with reference to the exact type of process,the factor of safety, etc.

In general it is not necessary to carry out the process under pressure.Because of the ease of operation in the absence of pressure, this ispreferred. It is an advantage of the present process. however, that itmay be carried out in a closed system to prevent loss of the solvent.

It will be noted in accordance with Equation 2 that the primaryby-product of the reaction in accordance with the invention is nitricacid which remains dissolved in the solvent along with any excessnitrogen pentoxide and any unreacted ethyleneurea. It is, therefore,possible that upon the accumulation of nitric acid in the nitratingsolution the reaction (1) may also take place with the formation ofwater as a secondary by-product. This may result in the disadvantagesreferred to heretofore in connection with the Presence of the water.

However, since the reaction is one in which both reactants may be insolution and the principal product is insoluble in the nitratingsolution and the by-product soluble, it is not so essential to massaction principles to employ means to remove the nitric acid as soon aspossible after it is formed.

In accordance with an embodiment of the invention which would bepreferably utilized in a continuous process, the nitric acid may beremoved substantially as fast as it is formed so as to prevent thereaction (1) and its attendant difficulties due to the formation ofwater.

In accordance with one embodiment of the process for removing nitricacid the nitrating solution is contacted with phosphorus pentoxide(P205). By this means the primary by-product of the reaction, nitricacid, is absorbed by the phosphorus pentoxide and, at least in part,reconverted to nitrogen pentoxide in accordance with, it is thought, thefollowing reaction:

If the solvent selected is one in which the nitrogen pentoxide andnitric acid are soluble, such as chloroform, but in which the phosphoruspentoxide and the metaphosphoric acid are insoluble, the nitratingsolution may be circulated over a bed of phosphorus pentoxide to havethe nitric acid removed.

By means of such a process, it is possible to provide a simple means ofindefinitely maintaining the purity of the nitrating solution and theonly variable will be the concentration of the nitrogen pentoxide in thesolvent. Even this may be eliminated as a variable by fortifying it witha solution of N204.

When the nitric acid is to be removed with phosphorus pentoxide theprocess may be carried out conveniently in either a batch or a.continuous operation. In a batch operation the nitrating solution may becontacted with the phosphorus pentoxide between batches. However, thisembodiment of the process is so well adapted to a continuous operationand these are so desirable on a commercial scale that this seems to bethe preferable commercial form. In one such embodiment the nitratingsolution may be continuously circulated, first through a mixing zonewith the ethyleneurea which is added either in solution or as a solidand in which zone the dintroethyleneurea is separated by illtraticn orsettling, following which the solution is then circulated through aregenerating zone which may be in the form of a bed of phosphoruspentoxide. In such a process the nitric acid, as fast as it is formed asthe primary product, is carried out of the nitrating zone and away fromthe ethylencurea. The nitric acid is removed by treatment with thephosphorus pentoxide beforethe solution is recontacted with additionalethyleneurea. If ethyleneurea is to be treated in a solid form it may bepassed coninuously through a treating chamber through which thenitrating solution is continuously flowing, preferably counter-current.A series of regenerating chambers may be provided so that one may beused while another is being charged with a fresh quantity of phosphoruspentoxide.

In another embodiment of the process the nitric acid formed may beremoved from the nitrating solution by means of a fluoride salt. Sodiumfluoride is the cheapest of the materials for this purpose and thisadaptation oi the invention will be described further using sodiumfluoride as illustrative.

By means of this process, in which nitrogen pentoxide is in solution inthe non-aqueous inert solvent and the sodium fluoride is insoluble inthe solvent, it is possible to provide a simple means of indefinitelymaintaining the purity of the nitrating solution and the only variablewill be the concentration of the nitrogen pentoxide in the solvent. Eventhis may be eliminated as a variable by fortifying it with a solution OfN205.

The process using the sodium fluoride may be operated in a batch orcontinuous manner in any of the ways suggested heretofore in connectionwith the use of phosphorus pentoxide. For example, the ethyleneurea maybe placed in the nitrogen pentoxide solution and the dinitroethyleneurcaremoved, following which sodium fluoride may be added to the solution toremove the nitric acid and the solution reused. In a continuous processthe solution may be circulated through a vessel containing sodiumfluoride in the manner previously described in connection with theremoval of the nitric acid with phosphorus pentoxide.

The amount of sodium fluoride which may be utilized also is notcritical. In general, it is desired to utilize sufficient sodiumfluoride to insure substantially complete adsorption of the nitric acid.The amount required many depend also on the frequency with which it isreplaced, and the exact process adapted. A counter-current system shoulduse a. lesser amount. In general, it may be preferred to utilize aproportion of about 1 part of sodium fluoride to about 2 parts oi theby-product nitric acid theoretically obtainable. This proportion ismerely illustra tire and may be varied over a wide range.

Without wishing to be bound by any theory as to the results obtainedwhen using sodium fluoride to remove nitric acid, the followingexplanation may be of assistance in understanding this aspect of theinvention.

It is thought that the sodium fluoride holds the acid through theso-called "hydrogen bond or "coordinate" linkage, sometimes referred toas a secondary valence. The fluorine atom being strongly clectronegativeacts as a proton acceptor and the hydrogen in the acid is attracted tothe fluorine and held through ionic forces. This explains why nitricacid, for example, which contains hydrogen may combine with thefluorides through a so-called secondary valence, whereas nitrogenpentoxide, which does not contain hydrogen, does not. The hydrogenbonded complex of the fluoride and the acid presumably, therefore, maybe viewed as where the full dash indicates a primary valence and wherethe dotted dash indicates the socaled hydrogen bond or secondaryvalence.

The phenomena described is referred to as an adsorption, and this is notintended to mean a strictly physical relationship between the acid andthe fluoride. The word is used as generic to a. physical or chemicalunion, or a combination thereof, particularly the possible chemicalcomplex involving the phenomena of the socalled hydrogen bonds.

In describing the applicability of the invention, using a fluoride toremove the nitric acid, we have illustrated it with the use of sodiumfluoride merely for convenience because of its availability, low cost,practicality, and eiflclency. It is to be understood, however, thatcertain other fluorides may be used, such as zinc fluoride, magnesiumfluoride, potassium fluoride, ammonium fluoride, etc. The words fluoridesalt" are intended to be generic to fluorides of these metals.

In view of the foregoing disclosure and many variations in carrying outthe invention, it may be suggested to one skilled in the art that allsuch variations are intended to be included within the scope of theinvention as fall within the following claims.

We claim:

1. A process of nitrating ethyleneurea which comprises treating it witha solution of nitrogen pentoxide dissolved in a non-aqueous solvent.

2. A process of nitratlng ethyleneurea which comprises treating it withnitrogen pentoxide dissolved in chloroform.

3. A process of nitrating ethyieneurea which comprises mixing a.solution of ethyleneurea in a non-aqueous solvent with a solution ofnitrogen pentoxide in a non-aqueous solvent.

4. A process of nitrating ethyleneurea which comprises treating it withit with a solution of nitrogen pentoxide dissolved in a non-aqueoussolvent in the proportion of about 5 to 50 grams of nitrogen pentoxideto cc. of solution, and maintaining a temperature of about 20 to 30 C.during the nitration.

5. A process of nitrating ethyleneurea which comprises treating it witha solution of nitrogen pentoxide dissolved in a non-aqueous solvent inthe proportion of about 5 to 50 'grams of nitrogen pentoxide to 100 cc.of solution, maintaining a temperature of about 20 to 30 C. during thenitration, and separating the dinitroethyleneurea from the solution.

6. A process of nitrating ethyleneurea which comprises treating it withnitrogen pentoxide dissolved in chloroform in the proportion of about 5to 50 grams of nitrogen pentoxide to 100 cc. of solution.

'7. A process of nitrating ethyleneurea which comprises treating it withnitrogen pentoxide dissolved in chloroform in the proportion .01 about 5to 50 grams of nitrogen pentoxide to 100 cc. of solution, maintaining atemperature of about -20 to 30 C. during the nitration, and separatingthe dinitroethyleneurea from the solution.

8. A process of nitrating ethyleneurea which comprises dissolving it inchloroform and addin the solution so formed with agitation to a solutionof nitrogen pentoxide in chloroform, the amount of the nitrogenpentoxide being at least that theoretically required to convert theethyleneurea to dinitroethyleneurea, removing the crystallinedinitroethyleneurea which forms as a precipitate, and washing and dryingthe precipitate.

9. A continuous process for manufacturing dinitroethyleneurea, whichcomprises continuously contacting ethyleneurea. and nitrogen pentoxidein a solvent in which both the soluble but in which thedinitroethyleneurea is insoluble, and separating the precipitateddinitroethyleneurea.

10. A continuous process for manufacturing dinitroethyieneurea, whichcomprises continuousiy contacting ethyieneurea and nitrogen pentoxidedissolved in chloroform, and separating the precipitateddinitroethyleneurea.

11. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously adding ethyleneurea to a solution of nitrogenpentoxid in a non-aqueous solvent in which the ethyleneurea is solublebut in which the dinitroethyleneurea is insoluble, and separating theprecipitated dinitroethyieneurea.

12. A continuous process for manufacturing dinitroethyleneurea whichcomprises continuously adding a solution of ethyleneurea in a nonaqueoussolvent to a solution of nitrogen pentoxide in a non-aqueous solvent.said solvent being one in which the ethyleneurea is soluble but in whichthe dinitroethyleneurea is insoluble, and separating the precipitateddinitroethyleneurea.

13. A continuous process for manufacturing dinitroethyleneurea whichcomprises continuousLv contacting ethyleneurea and nitrogen pentoxide ina non-aqueous solvent in which the Certificate of Correction Patent No.2,400,288.

ethyleneurea is soluble but in which the dinitroethyleneurea isinsoluble, and separating the precipitated dinitroethyieneurea, removingnitric acid formed in the reaction and reusing the solvent in thenitration of an additional quantity of ethyleneurea.

'14. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously adding ethyleneurea to a solution of nitrogenpentoxide in chloroform, and separating the precipitateddinitroethyleneurea.

15. A continuous process for manufacturin dinitroethyleneurea whichcomprises continu ously mixing a solution of ethyieneurea in chloroformwith a solution of nitrogen pentoxlde in chloroform, and separating theprecipitated dinitroethyleneurea.

16. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously contacting ethyleneurea and nitrogen pentoxide inchloroform, separating the precipitated dinitroethyleneur'ea. removingnitric acid from the chloroform and reusing the chloroform for nitratingan additional amount of ethyleneurea.

GEORGE V. CAESAR. MAX GOLDFRANK.

May 14, 1946.

GEORGE V. CAESAR ET AL.

It is hereby certified that errors appear 1n the numbered patentrequiring correction as follows: after as and before hydrocarbon inserta; page Ethylcneureau read Ethyleneurea; page read temperature; line (3with second occurrence, 5

Patent should be read with these corrections therein that the 3, firstcolumn, lllllt'. l r 34 b f f 2 read ,Q); page 4, seconr co umn, me eore 9 t rike out the words with it; and that the said Letters the recordof the case in the Patent Office.

Signed and sealed this 2d day of July, A. D. 1946.

[small] printed specification of the above Page 1, second column, lme27, 2, first column, lme 35, for 57, for temoprature same may conform toLESLIE FRAZER,

first Assistant Commissioner of Patents.

but in which the dinitroethyleneurea is insoluble, and separating theprecipitated dinitroethyleneurea.

10. A continuous process for manufacturing dinitroethyieneurea, whichcomprises continuousiy contacting ethyieneurea and nitrogen pentoxidedissolved in chloroform, and separating the precipitateddinitroethyleneurea.

11. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously adding ethyleneurea to a solution of nitrogenpentoxid in a non-aqueous solvent in which the ethyleneurea is solublebut in which the dinitroethyleneurea is insoluble, and separating theprecipitated dinitroethyieneurea.

12. A continuous process for manufacturing dinitroethyleneurea whichcomprises continuously adding a solution of ethyleneurea in a nonaqueoussolvent to a solution of nitrogen pentoxide in a non-aqueous solvent.said solvent being one in which the ethyleneurea is soluble but in whichthe dinitroethyleneurea is insoluble, and separating the precipitateddinitroethyleneurea.

13. A continuous process for manufacturing dinitroethyleneurea whichcomprises continuousLv contacting ethyleneurea and nitrogen pentoxide ina non-aqueous solvent in which the Certificate of Correction Patent No.2,400,288.

ethyleneurea is soluble but in which the dinitroethyleneurea isinsoluble, and separating the precipitated dinitroethyieneurea, removingnitric acid formed in the reaction and reusing the solvent in thenitration of an additional quantity of ethyleneurea.

'14. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously adding ethyleneurea to a solution of nitrogenpentoxide in chloroform, and separating the precipitateddinitroethyleneurea.

15. A continuous process for manufacturin dinitroethyleneurea whichcomprises continu ously mixing a solution of ethyieneurea in chloroformwith a solution of nitrogen pentoxlde in chloroform, and separating theprecipitated dinitroethyleneurea.

16. A continuous process for manufacturing dinitroethyieneurea whichcomprises continuously contacting ethyleneurea and nitrogen pentoxide inchloroform, separating the precipitated dinitroethyleneur'ea. removingnitric acid from the chloroform and reusing the chloroform for nitratingan additional amount of ethyleneurea.

GEORGE V. CAESAR. MAX GOLDFRANK.

May 14, 1946.

GEORGE V. CAESAR ET AL.

It is hereby certified that errors appear 1n the numbered patentrequiring correction as follows: after as and before hydrocarbon inserta; page Ethylcneureau read Ethyleneurea; page read temperature; line (3with second occurrence, 5

Patent should be read with these corrections therein that the 3, firstcolumn, lllllt'. l r 34 b f f 2 read ,Q); page 4, seconr co umn, me eore 9 t rike out the words with it; and that the said Letters the recordof the case in the Patent Office.

Signed and sealed this 2d day of July, A. D. 1946.

[small] printed specification of the above Page 1, second column, lme27, 2, first column, lme 35, for 57, for temoprature same may conform toLESLIE FRAZER,

first Assistant Commissioner of Patents.

